Charles Ellicott Commentary Judges 9:33

"and it shall be, that in the morning, as soon as the sun is up, thou shalt rise early, and rush upon the city; and, behold, when he and the people that are with him come out against thee, then mayest thou do to them as thou shalt find occasion." — Judges 9:33 (ASV)

As you will find occasion. —Literally, as in the margin, as thine hand shall find, as in 1 Samuel 10:7; 1 Samuel 25:8.